One person remains missing after a blast in a grain silo in Parana state triggers two more, authorities say.

One person remained missing on Thursday, a day after the explosion at the C Vale cooperative in Palotina, a city about 600km (372 miles) west of the Parana state capital, Curitiba. Parana is one of Brazil’s top grain-producing states.

“There was an explosion in one of the silos that triggered a second and a third,” Parana fire brigade spokesman Tiago Zajac told the Agence France-Presse news agency.

Video footage distributed on social and Brazilian media showed a large column of white smoke coming from the site and Palotina residents reported feeling a tremor as windows in several homes were blown out.

C Vale, a major producer of soybeans, wheat and corn that stores grain in 125 units across five Brazilian states and in Paraguay, confirmed in a statement that a “large-scale accident hit our central grain reception unit in Palotina”.

The company said the cause was “yet to be determined”.

Grain dust particles are highly combustible and can cause fires or explosions. The particles can be from wheat, oats, barley or other types of grain that form layers or become airborne in an enclosed space.

For a grain dust explosion to occur, experts say four elements have to be present: fuel, oxygen, confinement and a source of ignition.

“I’m deeply saddened by what happened at C Vale,” Brazilian Agriculture Minister Carlos Favaro wrote on the social media website X, formerly known as Twitter. “I express my condolences to the families of the victims.”

Acting Parana Governor Darci Piana headed to Palotina, home to about 35,000 people, with state secretaries to follow the rescue operations and provide support to the families, the government said.